Antibiotic resistance in staphylococci adherent to cortical bone.

The surface-adherent mode of bacterial growth has been shown to play a pivotal role in the persistent nature of infections involving retained foreign bodies, biomaterials, or dead bone (e.g., osteomyelitis). The hypothesis tested herein is that bone and implant materials--polytetrafluoroethylene (PTFE), and polymethylmethacrylate (PMMA)--provide a surface environment that promotes a type of bacterial growth characterized by an enhanced antibiotic resistance. The antibiotic resistance estimates of three staphylococcal subtypes were determined for organisms grown in an adherent state on the aforementioned surfaces as well as in their nonadherent or suspended state. Antibiotic resistance was found to vary with mode of bacterial growth. Secondly, for the staphylococcal subtypes, antibiotics and modes of growth studied herein, adherent growth on bone was associated with the most antibiotic resistance.